OLS, ordinary least square

OLS,普通最小二乘法
  • 文章类型: Journal Article
    未经批准:为了研究生长模型,形状,晶状体和眼球的发育关系,我们使用二维磁共振(MR)成像来研究体内选定眼部参数的与年龄相关的变化.
    UNASSIGNED:我们回顾性回顾了126例妊娠21至39周胎儿的MR图像。测量横向平面MR成像的眼部参数,包括晶状体直径(LD),前后晶状体直径(APLD),透镜表面积(LS),球形直径(GD),前后球直径(APGD),地球表面面积(GS)。每个生物特征与胎龄(GA)的生长模型,镜头和球体的纵横比(LD/APLD和GD/APGD),并通过统计分析研究了晶状体与眼球表面积之比(LS/GS)之间的增长关系。
    UNASSIGNED:大多数胎龄生物特征的生长模型是对数的,除了眼球直径(GD和APGD)显示出二次生长模式。我们的研究表明,在21-39周内,晶状体的横向直径始终大于前后直径(P<0.001)。此外,表面积比(LS/GS)随GA变化不显著(P=0.4908),LS的增加与GS的增加显着一致(P<0.001)。
    未经证实:整个胎儿生命中的晶状体形状可能参与该过程,形状从垂直椭圆体改变,球形到横向椭圆体,基于晶状体横向和前后直径的对数增加比率。同时,胎儿晚期的眼球长宽比可能意味着在妊娠期间逐渐呈球形。这项研究的列线图数据可以提供有关胎儿晶状体形态变化以及晶状体与眼球之间同步关系的适当信息。
    UNASSIGNED: To study the growth model, shape, and developmental relationship of lens and eyeball, we used two-dimensional Magnetic Resonance (MR) imaging to investigate gestationally age-related changes in the selected ocular parameters in vivo.
    UNASSIGNED: We retrospectively reviewed the MR images from 126 fetuses ranging from 21 to 39 weeks\' gestation. Ocular parameters on MR imaging of transverse plane were measured including lens diameter (LD), anteroposterior lens diameter (APLD), lens surface area (LS), globe diameter (GD), anteroposterior globe diameter (APGD), globe surface area (GS). The growth model of each biometric against gestational age (GA), aspect ratio of lens and globe (LD/APLD and GD/APGD), and growing relationship between the ratio of lens and globe surface area (LS/GS) were studied by statistical analysis.
    UNASSIGNED: The growth model of most biometry for gestational age is logarithmic, except for the diameter of the ocular globe (GD and APGD) showing a quadratic growth pattern. Our study showed that the lens was consistently larger in the transverse than the anteroposterior diameters during 21-39 weeks(P < 0.001). Besides, the ratio of surface area (LS/GS) was not significantly changing with GA(P = 0.4908), while the increase of LS was significantly accorded with that of GS(P < 0.001).
    UNASSIGNED: The lens shape throughout fetal life may take part in the process, shape changing from vertical ellipsoid, spherical to transversal ellipsoid, based on the logarithmically increased ratio of lens transverse and anteroposterior diameters. In the meanwhile, the aspect ratio of eyeball in late fetal life may imply a gradually spherical shape during gestation. Nomogram data from this study may provide appropriate information about morphological changes in the fetal lens and the synchronous relationship between lens and eyeball.
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  • 文章类型: Journal Article
    醛糖还原酶(AR)酶是开发治疗高血糖引起的健康并发症如视网膜病变的重要靶酶。等。在本研究中,使用遗传算法-多元线性回归(GA-MLR)技术,对226个报道的AR抑制剂(ARi)分子的数据集进行定量结构活性关系(QSAR)评估.多准则决策(MCDM)分析提供了两个基于五个变量的QSAR模型,这些模型在各种统计参数中都具有可接受的高性能,例如,R2=0.79-0.80,Q2LOO=0.78-0.79,Q2LMO=0.78-0.79。QSAR模型分析揭示了一些分子特征,这些特征在决定分子对AR的抑制效力中起着至关重要的作用,例如;分子质心2µ内的疏水氮,由三个和四个键与氢键供体原子分开的非环碳,sp2杂化的氧与sp2杂化的碳原子由四个键分开,等。14在硅产生的命中,使用化合物18(来自当前数据集的最有效的ARi,pIC50=8.04M)作为模板,基于QSAR的虚拟筛选(QSAR-VS)提供的支架5具有比模板化合物18更好的ARi活性(pIC50=8.05M)。此外,化合物18(对接评分=-7.91kcal/mol)和支架5(对接评分=-8.08kcal/mol)与AR的分子对接,揭示它们都通过氢键和疏水相互作用占据AR受体结合位点中的特定口袋。分子动力学模拟(MDS)和MMGBSA通过揭示结合位点残基与支架5和化合物18相互作用以产生类似于共结晶配体构象的稳定复合物的事实来研究对接结果。QSAR分析,分子对接,和MDS结果都是一致和互补的。QSAR-VS成功鉴定出一种更有效的新型ARi,可用于开发治疗糖尿病的治疗剂。
    The aldose reductase (AR) enzyme is an important target enzyme in the development of therapeutics against hyperglycaemia induced health complications such as retinopathy, etc. In the present study, a quantitative structure activity relationship (QSAR) evaluation of a dataset of 226 reported AR inhibitor (ARi) molecules is performed using a genetic algorithm - multi linear regression (GA-MLR) technique. Multi-criteria decision making (MCDM) analysis furnished two five variables based QSAR models with acceptably high performance reflected in various statistical parameters such as, R2 = 0.79-0.80, Q2 LOO = 0.78-0.79, Q2 LMO = 0.78-0.79. The QSAR model analysis revealed some of the molecular features that play crucial role in deciding inhibitory potency of the molecule against AR such as; hydrophobic Nitrogen within 2 Å of the center of mass of the molecule, non-ring Carbon separated by three and four bonds from hydrogen bond donor atoms, number of sp2 hybridized Oxygen separated by four bonds from sp2 hybridized Carbon atoms, etc. 14 in silico generated hits, using a compound 18 (a most potent ARi from present dataset with pIC50 = 8.04 M) as a template, on QSAR based virtual screening (QSAR-VS) furnished a scaffold 5 with better ARi activity (pIC50 = 8.05 M) than template compound 18. Furthermore, molecular docking of compound 18 (Docking Score = -7.91 kcal/mol) and scaffold 5 (Docking Score = -8.08 kcal/mol) against AR, divulged that they both occupy the specific pocket(s) in AR receptor binding sites through hydrogen bonding and hydrophobic interactions. Molecular dynamic simulation (MDS) and MMGBSA studies right back the docking results by revealing the fact that binding site residues interact with scaffold 5 and compound 18 to produce a stable complex similar to co-crystallized ligand\'s conformation. The QSAR analysis, molecular docking, and MDS results are all in agreement and complementary. QSAR-VS successfully identified a more potent novel ARi and can be used in the development of therapeutic agents to treat diabetes.
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  • 文章类型: Journal Article
    未经评估:健康的社会决定因素(SDOH)产生了广泛的预期寿命(LE)差异。在中国,从空间角度来看,发现有限的文献报道了连续一段时间在生态水平上SDOH和LE之间的关联。本研究旨在确定存在,量化大小,并解释了中国SDOH和LE之间的关联。
    UNASSIGNED:省级LE是根据2005-2020年中国国家死亡率监测系统的死亡率记录估算的。空间面板Durbin模型用于研究LE相关的SDOH代理。引入空间溢出效应来解释SDOH在长期和短期对LE差异的直接和间接影响。
    未经批准:全国,从2005年到2020年,LE从73.1年(95%置信区间(CI):71.3,74.4年)增加到77.7年(95CI:76.5,78.7年)。观察到LE的空间分布不均,在沿海地区具有高-高聚集性,在西部地区具有低-低聚集性。本地,据估计,SDOH代理与LE的增加有统计学意义,包括国内生产总值(系数:0.02,95CI:0.00,0.03),基尼系数(系数:2.35,95CI:1.82,2.88),医疗机构床位数(系数:0.02,95CI:0.00,0.05)和常住人口自然增长率(系数:0.02,95CI:0.01,0.02)。LE相关SDOH代理在长期和短期的直接和间接效应分解表明,GDP,城镇化率,失业率,受教育程度,基尼系数,医疗机构的床位数量,性别比例,常住人口的总依赖率和自然增长率不仅影响当地的LE,但也对地理邻居产生了空间溢出效应。
    未经评估:中国省级存在LE的空间变异。SDOH关于社会经济发展和公平,医疗资源,以及人口特征不仅影响了当地规模的LE差异,而且影响了附近省份之间的LE差异。应考虑到SDOH代理政策的外部性,以在全国范围内促进卫生公平。应巩固基于人口战略的综合方法,以优化支持性社会经济环境,缩小区域差距,以减少健康差距并增加LE。
    UNASSIGNED:国家重点研究发展计划(批准号2018YFC1315301);教育部人文社会科学总计划(批准号18YJC790138)。
    UNASSIGNED: Social determinants of health (SDOH) produce a broad range of life expectancy (LE) disparities. In China, limited literatures were found to report association between SDOH and LE at ecological level during a consecutive period of time from the spatial perspectives. This study aimed to determine the existence, quantify the magnitude, and interpret the association between SDOH and LE in China.
    UNASSIGNED: Provincial-level LE were estimated from mortality records during 2005-2020 from National Mortality Surveillance System in China. A spatial panel Durbin model was used to investigate LE associated SDOH proxies. Spatial spillover effects were introduced to interpret direct and indirect effects caused by SDOH during long-term and short-term period on LE disparities.
    UNASSIGNED: Nationwide, LE increased from 73.1 (95% confidence interval (CI): 71.3, 74.4) years to 77.7 (95%CI: 76.5, 78.7) years from 2005 to 2020. Unequally spatial distribution of LE with High-High clustering in coastal areas and Low-Low clustering in western regions were observed. Locally, it was estimated that SDOH proxies statistically significant related to an increase of LE, including GDP (coefficient: 0.02, 95%CI: 0.00, 0.03), Gini index (coefficient: 2.35, 95%CI: 1.82, 2.88), number of beds in health care institutions (coefficient: 0.02, 95%CI: 0.00, 0.05) and natural growth rate of resident population (coefficient: 0.02, 95%CI: 0.01, 0.02). Direct and indirect effects decomposition during long-term and short-term of LE associated SDOH proxies demonstrated that GDP, urbanization rate, unemployment rate, education attainment, Gini index, number of beds in health care institutions, sex ratio, gross dependence ratio and natural growth rate of resident population not only affected local LE, but also exerted spatial spillover effects towards geographical neighbors.
    UNASSIGNED: Spatial variations of LE existed at provincial-level in China. SDOH regarding socioeconomic development and equity, healthcare resources, as well as population characteristics not only affected LE disparities at local scale but also among nearby provinces. Externalities of policy of those SDOH proxies should be took into consideration to promote health equity nationally. Comprehensive approaches on the basis of population strategy should be consolidated to optimize supportive socioeconomic environment and narrow the regional gap to reduce health disparities and increase LE.
    UNASSIGNED: National Key Research & Development Program of China (Grant No.2018YFC1315301); Ministry of Education of China Humanities and Social Science General Program (Grant No.18YJC790138).
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  • 文章类型: Journal Article
    在目前的工作中,根据OECD指南,对一系列肽型SARS-CoV主要蛋白酶(MPro)抑制剂进行了广泛的QSAR(定量结构活性关系)分析。该分析旨在鉴定控制肽型化合物的MPro抑制活性的显著和隐藏的结构特征。QSAR分析基于62个肽型化合物的数据集,其导致产生统计上稳健且高度预测性的多个模型。所有开发的模型都经过了广泛的验证,并满足许多统计参数的阈值(例如R2​=0.80-0.82,Q2loo​=0.74-0.77,Q2LMO​=0.66-0.67)。开发的QSAR模型确定了芳香碳原子七个键内sp2杂化氧原子的数量,拓扑距离为3的碳和氮原子的存在以及原子对的其他相互关系是重要的药理作用。因此,目前的QSAR模型具有定性(描述性QSAR)和定量(预测性QSAR)方法的良好平衡,因此可用于未来修饰用于抗SARS-CoV活性的肽型化合物。
    In the present work, an extensive QSAR (Quantitative Structure Activity Relationships) analysis of a series of peptide-type SARS-CoV main protease (MPro) inhibitors following the OECD guidelines has been accomplished. The analysis was aimed to identify salient and concealed structural features that govern the MPro inhibitory activity of peptide-type compounds. The QSAR analysis is based on a dataset of sixty-two peptide-type compounds which resulted in the generation of statistically robust and highly predictive multiple models. All the developed models were validated extensively and satisfy the threshold values for many statistical parameters (for e.g. R2 ​= ​0.80-0.82, Q2 loo ​= ​0.74-0.77, Q 2 LMO  ​= ​0.66-0.67). The developed QSAR models identified number of sp2 hybridized Oxygen atoms within seven bonds from aromatic Carbon atoms, the presence of Carbon and Nitrogen atoms at a topological distance of 3 and other interrelations of atom pairs as important pharmacophoric features. Hence, the present QSAR models have a good balance of Qualitative (Descriptive QSARs) and Quantitative (Predictive QSARs) approaches, therefore useful for future modifications of peptide-type compounds for anti- SARS-CoV activity.
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  • 文章类型: Journal Article
    统计中介分析是试验中经常使用的方法,解开干预对特定结果变量影响的潜在途径。多年来,已经提出了几种方法,例如普通最小二乘(OLS)回归,结构方程模型(SEM),和潜在结果框架。大多数应用研究人员不知道,当应用于具有连续中介和结果变量的中介模型时,这些方法在数学上是等效的。因此,本文的目的是证明OLS回归之间的相似性,SEM,以及三个中介模型中的潜在结果框架:1)一个粗略的模型,2)混杂调整模型,和3)具有暴露-媒介相互作用的相互作用项的模型。
    一项纳入546名学童的随机对照试验的次要数据分析。在我们的数据示例中,中介变量和结局变量均为连续变量.我们比较了总数的估计值,直接和间接影响,比例介导,OLS回归间接效应的95%置信区间(CI),SEM,和潜在结果框架。
    OLS回归,SEM,潜在结果框架在粗中介模型中产生了相同的效果估计,混杂调整的调解模型,以及具有暴露-中介相互作用的相互作用项的中介模型。
    自从OLS回归以来,SEM,潜在结果框架在三个具有连续中介和结果变量的中介模型中产生相同的结果,研究人员可以继续使用最方便的方法。
    UNASSIGNED: Statistical mediation analysis is an often used method in trials, to unravel the pathways underlying the effect of an intervention on a particular outcome variable. Throughout the years, several methods have been proposed, such as ordinary least square (OLS) regression, structural equation modeling (SEM), and the potential outcomes framework. Most applied researchers do not know that these methods are mathematically equivalent when applied to mediation models with a continuous mediator and outcome variable. Therefore, the aim of this paper was to demonstrate the similarities between OLS regression, SEM, and the potential outcomes framework in three mediation models: 1) a crude model, 2) a confounder-adjusted model, and 3) a model with an interaction term for exposure-mediator interaction.
    UNASSIGNED: Secondary data analysis of a randomized controlled trial that included 546 schoolchildren. In our data example, the mediator and outcome variable were both continuous. We compared the estimates of the total, direct and indirect effects, proportion mediated, and 95% confidence intervals (CIs) for the indirect effect across OLS regression, SEM, and the potential outcomes framework.
    UNASSIGNED: OLS regression, SEM, and the potential outcomes framework yielded the same effect estimates in the crude mediation model, the confounder-adjusted mediation model, and the mediation model with an interaction term for exposure-mediator interaction.
    UNASSIGNED: Since OLS regression, SEM, and the potential outcomes framework yield the same results in three mediation models with a continuous mediator and outcome variable, researchers can continue using the method that is most convenient to them.
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